Objective: Tumoral calcinosis is an uncommon lesion, composed of ectopic calcified tissue, most commonly seen in the large joints of the hips, knees, shoulders, and elbows. The involvement of the hand in a healthy patient is extremely rare, and therefore this condition can cause diagnostic confusion. The purpose of this report is to describe one case of idiopathic tumoral calcinosis that occurred in the left hand of a 35-year-old healthy female patient. Methods: The patient presented with 2-day history of acutely swelling and painful left hand middle finger metacarpal phalangeal joint without any precipitants. Results: All biochemical, radiological, and histopathological evidence suggested idiopathic tumoral calcinosis of the hand. Conclusions: In this case, surgery provided the patient with instant symptomatic relief and full functional recovery of that joint.